Tracheostomy cannula

ABSTRACT

A tracheostomy cannula for use in a tracheostoma is described, which is provided with a hose-like outer cannula into which an inner cannula, which is also hose-like, can be guided and can be locked to the outer cannula at the proximal part in order to form a cannula tube, wherein a cannula plate (3) for application to the neck is fitted in the proximal area of the outer cannula (1), through which the proximal part of the outer cannula reaches (1). It is proposed that the cannula tube is mounted so that it is pivotable about at least two spatial axes (X, Y) with respect to the cannula plate (3).

The invention relates to a tracheostomy cannula for insertion in atracheostoma, in accordance with the preamble of claim 1. It is providedwith a hose-like outer cannula, inside which an inner cannula, which isalso hose-like, can be guided and locked to the proximal part of theouter cannula, whereby in the proximal area of the outer cannula, acannula plate for placing on the neck of the patient is fitted. Theouter cannula and inner cannula together form the cannula tube.

Tracheostomy cannulas of this type with a cannula plate pivotable aboutone axis only have been long known. Reference is made in this connectionto U.S. Pat. No. 5,067,496, EP-0 107 779 B1, EP-0 037 719 B1, U.S. Pat.No. 4,852,565 and U.S. Pat. No. 4,009,720 in the patent literature.

Tracheostomy cannulas of this type are inserted in a tracheostomaresulting from an operation, in order to keep it open until it heals.There are circumstances, however, in which a tracheostomy cannula mustremain permanently in the tracheostoma. In other cases, the tracheostomycannula assists artificial respiration.

The outer cannula can be inserted in the trachea, widening thetracheostoma with the aid of a so-called guide rod (stylet orobturator). The outer cannula keeps the tracheostoma open and needs onlyto be removed from time to time for cleaning. On the proximal side ofthe outer cannula there is fitted a so-called cannula plate, which liesagainst the patient's neck when the tracheostomy cannula is in thetracheostoma. The cannula plate prevents, inter alia, the tracheostomycannula from being inserted too far into the trachea or from slidingdown into it.

The correspondingly configured hose-like inner cannula fits exactlyinside the outer cannula, and can be easily removed from it for frequentcleaning. This has the advantage that the outer cannula does not alsohave to be removed from the trachea and the tracheostoma, which couldotherwise result in pain and injuries.

The tracheostomy cannulas known from the documents listed above have acannula plate with respect to which the cannula tube is mountedpivotally about one axis, that is to say about the horizontal axis. Forthis purpose, the cannula plate is provided with an aperture throughwhich the outer cannula reaches. Two pegs project into the aperture,which engage with corresponding holding means in the external area ofthe outer cannula such that the cannula tube is pivotable in a certainrange of approximately ±45° with respect to the cannula plate. A degreeof wearer comfort is produced by means of this pivoting, to the extentthat when the patient bends or lifts his or her head, the tracheostomycannula can adjust its position to a certain degree so that the painwhich a patient feels when, for example, the cannula is pressed againstthe front or rear wall of the trachea, is reduced.

Nevertheless, the resulting wearer comfort of the known tracheostomycannulas is not yet satisfactory.

A tracheostomy cannula of the type described in the preamble is knownfrom U.S. Pat. No. 4,686,977. In this a tracheostomy cannula isdescribed wherein the cannula plate is mounted by means of a ball jointin the proximal part of the cannula. This type of mounting allows thepivoting of the cannula tube with respect to the cannula about the threespatial axes X, Y and Z. This proposal provided a theoretical approachas to how the wearer comfort of such a tracheostomy cannula could beimproved. However, the production of this tracheostomy cannula ran intodifficulties. There is, on the one hand, insufficient pivoting of thecannula tube with respect to the cannula plate, as the outer half-shelljaw has to enclose the ball in the joint to a comparatively large degreein the interests of safety, as otherwise there is the danger of thecannula becoming detached from the mounting and falling into thetrachea. On the other hand, the fixing of the inner cannula is difficultto effect, in particular having regard to the replacement of the innercannula which has to be done very frequently. The document describeddoes not offer any proposals for solutions to the fixing of the innercannula. The known types of fixing were therefore conceivable, such asby means of a bayonet fitting. However, if the connection were madeusing a bayonet fitting, there would be a movement about the thirdspatial axis Z. This rotation is dangerous to the patient, however, bothwhen awake and when sedated, for example, as without additional measuresthe cannula tube presses too hard laterally against the trachea wall.

Given this background, the object of the present invention is to furtherdevelop a tracheostomy cannula of the type described in the preamblesuch that a sufficient degree of pivoting about two spatial axes ispossible, and the pivoting is produced in relatively simple technicalmanner.

This object is solved according to the invention by means of thetracheostomy cannula with the features of the characterising part ofclaim 1. Further advantageous embodiments result from the dependentclaims.

It is firstly provided that the ability to pivot about the spatial Yaxis is produced by means of a ring gripping around the outer cannulaand rotatably mounted thereupon, and the ability to pivot about thespatial X axis is provided by means of rotatable mounting of the cannulaplate on the ring. If the cannula plate is ideally considered as a ring,the invention is effected in that two rings rotatable with respect toone another, that is to say the inner ring with respect to the outerring (cannula plate), are pivotally mounted on the outer cannula. Thisimplementation is relatively simple in terms of construction, but veryeffective and inexpensive.

The rotatable mounting, in the previously described case, of the ring onthe outer cannula and of the cannula plate on the ring, is preferablyprovided by pegs, which can be configured in correspondingly configuredrecesses in the canula, the ring and the cannula plate. This depends onwhere the pegs are arranged.

The dimensions in the case previously described are preferably selectedsuch that the cannula tube is pivotable with respect to the cannulaplate about the Y axis by ±25° and about the X axis by ±60°.

The invention will hereinafter be described in more detail with the aidof an embodiment with reference to the drawings. In these is shown, in:

FIG. 1 a view of the tracheostomy cannula with a cuff and controlballoon,

FIG. 2 a sectional view through the tracheostomy cannula according toFIG. 1,

FIG. 3 a detail view in the direction of the arrow III in FIG. 1,

FIG. 4 a similar view as in FIG. 3, however with a cannula plate pivotedto one side,

FIG. 5 a similar view as in FIG. 4, with the cannula plate pivoted tothe other side,

FIG. 6 a detail view of the proximal area of the tracheostomy cannulaaccording to FIG. 1 with a cannula plate pivoted in one direction aboutthe X-axis, and

FIG. 7 a similar view as in FIG. 6 with a cannula plate pivoted to theother side.

Hereinafter, like parts have like designations.

FIG. 1 gives the first rough overview of the tracheostomy cannulaaccording to the invention. It is composed of an outer cannula 1, intowhich an inner cannula (not shown in FIG. 1) is guided. A connectingpart 16 in accordance with DIN ISO 5356-1 (1987) which projects from thepatient's tracheostoma is moulded onto the inner cannula. When thetracheostomy cannula has been completely inserted through thetracheostoma into the trachea, the cannula plate 3, which is fitted tothe proximal area of the outer cannula 1, lies against the patient'sneck.

The cannula tube, composed of the outer cannula and the inner cannula,is arranged such that it can pivot about two spatial axes with respectto the cannula plate (3) by means of the parts labelled with thedesignations 4, 5 and 6, as will be explained later in more detail.

Lying at the front in the distal area of the outer cannula 1, there isarranged a balloon or cuff 7 which can be inflated by means of an airline 8 outside the body, so that the distal end of the tracheostomycannula can be brought into a defined position with respect to the wallof the trachea and so that a seal between the outer cannula and air tubecan be produced. This is done by inflating the balloon or cuff 7 fromthe exterior and is controlled by the control balloon 9.

Details of the constructional design of the tracheostomy cannula can beseen from FIG. 2, which shows a sectional view. Here, it is clearlyevident how the inner cannula 10 is guided into the outer cannula 1. Theability of the canula plate 3 to pivot about the axis, shown in thedrawing as horizontal (Y axis) is here produced in that a ring 4 gripsthe outer cannula 1 in the proximal area and is rotatably mounted uponit by means of the peg 5 projecting into the inside of the ring, whichengage with cut-outs or recesses 6 in a shoulder 17 moulded onto theproximal end of the outer cannula 1. To make the ability to pivot aboutthe axis (X axis) perpendicular to the plane of the drawing possible,the cannula plate 3 is mounted in a rotatable manner, connected to thering 4. This can, however, be more clearly seen in FIGS. 3 to 5. Asclearly illustrated in FIG. 2, the X and Y axes are disposedsubstantially parallel to the cannula plate 3 and the X a is disposedperpendicular to the Y axis.

FIG. 3 shows the enlarged partial view, in the direction of the arrowIII in FIG. 1, of the proximal area of the tracheostomy cannula. At thetop is the system of coordinates to which details of the spatial axesrelate.

FIG. 3 firstly shows the rotatable mounting of the cannula plate 3 onthe ring 4. From the ring there project two pegs 5 which engage with twocut-outs or eyelets 6 which are moulded in the cannula plate 3. Theability to pivot about the X axis in the system of coordinates set outis obtained in this way.

FIG. 3 again shows the connecting piece 16 and the outer cannula 1. Thehose 8 which leads to the balloon 7 (FIG. 1) is also shown, and how itis fixed through and into a retaining eyelet 18 onto the ring 4.

FIGS. 4 and 5 very clearly show the possibilities for pivoting about theY axis which is made possible by the mounting which was described withreference to FIG. 2.

FIGS. 6 and 7 show the view of the proximal area of the tracheostomycannula displaced by 90° with respect to FIGS. 3 to 5, that is to sayseen from the right. The ability of the cannula plate 3 to pivot aboutthe X axis is clearly shown. The details of the mounting were describedwith reference to FIG. 3.

I claim:
 1. Trachcostomy cannula for use in a tracheostoma, said cannulacomprising:a tubular outer cannula (1) having a proximal part and adistal part; a tubular inner cannula (10) guided and locked within theouter cannula (1) at the proximal part in order to form a cannula tubehaving a tube axis; a cannula plate (3) for attachment to a patient'sneck, the cannula plate (3) receiving the proximal part of the outercannula of the cannula tube, the cannula tube mounted such that it isable to pivot about X and Y spatial axes with respect to the cannulaplate (3), the X and Y axes disposed substantially parallel to thecannula plate (3) and substantially perpendicular to the tube axis, theX axis disposed perpendicular to the Y axis and the canula tubesupported for pivotal movement about the Y axis; means for pivoting thecannula tube about the Y axis obtained by a ring (4) gripping around theouter cannula (1), the ring (4) pivotally mounted on the outer cannulafor pivotal movement of the X axis relative to the tube axis; and meansfor pivoting the canoula tube about the X axis obtained by pivotalmounting of the cannula plate (3) on the ring (4).
 2. Tracheostomycannula according to claim 1, characterised in that the range ofpivoting about the Y axis is ±25° and about the X axis is ±60°. 3.Tracheostomy cannula according to claim 1, characterised in that thepivotal mounting of the ring (4) on the outer cannula (1) and of thecannula plate (3) on the ring (4) is effected by pegs (5) which engagewith correspondingly configured cut-outs (6).
 4. Tracheostomy cannulaaccording to claim 2, characterised in that the pivotal mounting of thering (4) on the outer cannula (1) and of the cannula plate (3) on thering (4) is effected by pegs (5) which engage with correspondinglyconfigured cut-outs (6).